Once in service, many, if not most, structures experience corrosion in response to their exposure to the elements, such as rain, humidity, elevated temperatures, salt and other chemicals, and the like. For example, many buildings and vehicles, such as ships and automobiles, may experience corrosion following exposure to the elements over time.
As corrosion may cause the integrity of the structure to degrade, it may be desirable in at least some application to prevent or at least reduce the rate of corrosion. As such, coatings have been developed that at least partially inhibit corrosion. For example, coatings that include chrome may reduce the rate at which the underlying structure corrodes. However, the corrosion inhibiting coating may disadvantageously increase the cost of the resulting structure and/or may introduce other disadvantages. For example, at least some corrosion inhibiting coatings may be potentially harmful to the environment such that special precautions are taken, both while coating the structure and then when disposing of the coated structure, thereby disadvantageously increasing the costs associated with the structure. Additionally, corrosion inhibiting coatings may be exhausted over time, thereby reducing the inhibition to corrosion provided by the coating. For example, a coating that includes chrome may change over time with the chrome leaching from the coating so as to reduce the corrosion inhibition otherwise provided by the coating.
In addition to or instead of efforts to inhibit the corrosion of various structures, the structures may be inspected, such as on a periodic or other scheduled basis, in order to detect corrosion and, if detected, to remediate the deleterious effects of the corrosion. While the visible regions of a structure may be inspected relatively easily such that inspections may be conducted with regularity, at least those regions of a structure that are hidden from view, such as those regions of a structure that require disassembly of at least a portion of the structure in order to access and to inspect the region may only be inspected occasionally because of the time and expense associated with the inspection process. Moreover, the disassembly associated with the inspection of otherwise inaccessible regions of the structure may, in some instances, damage the structure or otherwise cause portions of the structure to need to be replaced, thereby further increasing the time and expense associated with such an inspection.
By way of example, FIG. 1 depicts an interior region 10 of an aircraft. Although it may be desirable to detect corrosion of the illustrated interior region of the aircraft, at least a portion of the interior region, such as the circled regions 12, may be hidden from view and may therefore require at least partial disassembly of the interior region of the aircraft in order to conduct a complete inspection.
To facilitate the inspection of regions of a structure that are not visible without requiring disassembly of a portion of the structure, inspection techniques utilizing ultrasonic signals or electromagnetic currents or signals have been developed. While these inspection techniques may be useful in at least some circumstances, these inspection techniques may be limited in their application due to, for example, the underlying materials from which the structure is fabricated, the configuration of the structure and the like.
The foregoing inspection techniques, such as the disassembly of a portion of the structure in order to visually inspect the structure or the inspection of a structure utilizing ultrasonic or electromagnetic inspection techniques, generally require the structure to be taken out service for some period of time. As a result, such inspections are generally only performed periodically or in accordance with a predefined schedule. For example, some structures that are inspected by disassembling a portion of the structure in order to visibly inspect that portion of the structure may only be fully inspected every few years, such as every five or six years. Thus, the effects of corrosion on that portion of the structure during the period of time between inspections may cause degradation of the structure and may require more extensive repairs or rework of the structure than if the structure had been inspected more frequently and the corrosion detected closer to its onset.
As such, it would be desirable to provide improved techniques for detecting corrosion including, for example, corrosion that may occur in regions of a structure that are only visible following the partial disassembly of the structure.